Scrambles Amongst the Alps in the Years 1860–69 · Chapter
H: Denudation in the Valley of the Durance explained
In 1869, while walking up the Valley of the Durance, Whymper discovers remarkable natural pillars formed from an old moraine.
What happens
In 1869, while walking up the Valley of the Durance, Whymper discovers remarkable natural pillars formed from an old moraine. He examines their composition, deduces their glacial origin, and discusses the processes of denudation by rain and running water, contrasting them with the formation of similar pillars near Botzen.
Themes in this chapter
Scientific Observation
Whymper meticulously examines the pinnacles' composition, extracts rock fragments, and interprets the evidence of glacial action and denudation.
Exploration and Discovery
Whymper's spontaneous scramble up the hillside leads to the discovery and analysis of the unusual natural pillars.
Characters to notice
- Edward Whymper
Narrator and observer; scrambles up to examine the pinnacles and deduces their glacial origin.
- Sir Charles Lyell
Referenced for his explanation of the formation of the Botzen pillars via boulder protection.
Key passages
“I scrambled up, and found the remarkable natural pillars which are represented in the annexed engraving.”
Whymper climbed the slope and discovered the striking stone pillars shown in the illustration.
Describes the initial discovery of the pinnacles.
“From these indications, and from the situation of the pinnacles, I concluded that they had been formed out of an old moraine.”
Based on the evidence and location, Whymper inferred that the pillars originated from an ancient moraine.
Whymper's geological deduction about the origin of the pillars.
“I imagine that the largest of the Sachas pinnacles owe their existence to the portions of the moraine out of which they are formed having been studded with a greater quantity of stones and small boulders than the portions of the moraine which formerly filled the gaps between them.”
Whymper suggests that the largest pillars survived because the moraine material around them contained more stones and boulders, making them more resistant to erosion than the surrounding gaps.
Whymper's hypothesis on the differential erosion that shaped the pinnacles.